35
discharged and to ensure the motor housing has been flooded.
Be sure the loop flow center provides adequate flow through
the unit by checking pressure drop across the heat exchanger.
Compare the results to the data in Table 26.
Table 26 — Waterside Pressure Drop
Antifreeze —
In areas where entering loop temperatures
drop below 40°F or where piping will be routed through areas
subject to freezing, antifreeze is needed.
Alcohols and glycols are commonly used as antifreeze
agents. Freeze protection should be maintained to 15°F below
the lowest expected entering loop temperature. For example, if
the lowest expected entering loop temperature is 30°F, the
leaving loop temperature would be 22 to 25°F. Therefore, the
freeze protection should be at 15°F (30°F – 15°F = 15°F).
Calculate the total volume of fluid in the piping system. See
Table 27. Use the percentage by volume in Table 28 to
determine the amount of antifreeze to use. Antifreeze concen-
tration should be checked from a well mixed sample using a
hydrometer to measure specific gravity.
FREEZE PROTECTION SELECTION — The 30°F FP1
factory setting (water) should be used to avoid freeze damage
to the unit.
Once antifreeze is selected, the JW3 jumper (FP1) should
be clipped on the control to select the low temperature (anti-
freeze 13°F) set point to avoid nuisance faults.
Cooling Tower/Boiler Systems —
These systems
typically use a common loop temperature maintained at 60 to
90°F. Carrier recommends using a closed circuit evaporative
cooling tower with a secondary heat exchanger between the
tower and the water loop. If an open type cooling tower is used
continuously, chemical treatment and filtering will be necessary.
Table 27 — Approximate Fluid Volume (gal.)
per 100 Ft of Pipe
LEGEND
NOTE: Volume of heat exchanger is approximately 1.0 gallon.
Table 28 — Antifreeze Percentages by Volume
OPERATION
Power Up Mode —
The unit will not operate until all the
inputs, terminals and safety controls are checked for normal
operation.
NOTE: The compressor will have a 5-minute anti-short cycle
upon power up.
Units with Complete C or Deluxe D Controls
STANDBY — Y and W terminals are not active in Standby
mode; however, the O and G terminals may be active, depend-
ing on the application. The compressor will be off.
COOLING — Y and O terminals are active in Cooling mode.
After power up, the first call to the compressor will initiate a
270 to 300 second random start delay and a 5-minute anti-short
cycle protection time delay. After both delays are complete, the
compressor is energized.
NOTE: On all subsequent compressor calls the random start
delay is omitted.
HEATING STAGE 1 — Terminal Y is active in heating
stage 1. After power up, the first call to the compressor will
initiate a 270 to 300 second random start delay and a 5-minute
anti-short cycle protection time delay. After both delays are
complete, the compressor is energized.
NOTE: On all subsequent compressor calls the random start
delay is omitted.
50PC
UNIT
SIZE
WATER FLOW
RATE
(gpm)
WATERSIDE
PRESSURE
DROP (psi)
WATERSIDE
PRESSURE
DROP WITH
2-WAY FLOW
CONTROL
VALVE (psi)
007
1.0
0.3
0.5
2.0
1.1
1.8
3.0
2.3
3.8
009
1.0
0.5
0.6
2.0
1.7
2.3
3.0
3.5
5.0
012
1.5
1.0
1.4
2.5
2.6
3.6
3.5
4.8
6.7
015
2.0
1.9
2.5
3.0
3.9
5.3
4.0
6.5
9.1
018
2.5
1.1
2.1
4.0
2.7
5.2
5.0
4.0
8.0
024
3.0
1.7
2.0
4.0
2.8
3.4
6.0
5.8
7.2
030
4.0
2.0
2.6
6.0
4.2
5.6
8.0
7.0
9.6
036
4.5
1.6
2.4
6.0
2.6
4.0
9.0
5.4
8.6
041
5.0
2.0
3.0
8.0
4.6
7.2
11.0
8.2
13.1
042
5.0
2.0
3.0
8.0
4.6
7.2
11.0
8.2
13.0
048
6.0
0.8
1.4
8.0
1.4
2.5
12.0
2.8
5.4
060
7.5
1.4
2.4
10.0
2.3
4.1
15.0
4.8
8.8
070
9.0
2.0
3.4
12.0
3.4
5.9
18.0
7.0
12.7
IMPORTANT: All alcohols should be pre-mixed and
pumped from a reservoir outside of the building or
introduced under water level to prevent fuming.
PIPE
DIAMETER (in.)
VOLUME (gal.)
Copper
1
4.1
1.25
6.4
1.5
9.2
Rubber Hose
1
3.9
Polyethylene
3
/
4
IPS SDR11
2.8
1 IPS SDR11
4.5
1
1
/
4
IPS SDR11
8.0
1
/
2
IPS SDR11
10.9
2 IPS SDR11
18.0
1
1
/
4
IPS SCH40
8.3
1
1
/
2
IPS SCH40
10.9
2 IPS SCH40
17.0
IPS
—
Internal Pipe Size
SCH
—
Schedule
SDR
—
Standard Dimensional Ratio
ANTIFREEZE
MINIMUM TEMPERATURE FOR FREEZE
PROTECTION (°F)
10
15
20
25
Methanol (%)
25
21
16
10
100% USP Food Grade
Propylene Glycol (%)
38
30
22
15
Ethanol (%)
29
25
20
14
